First Case of Endoscopic Resection for Left Atrial Appendage Aneurysm with Suspected Viral Myocarditis: A Multimodal Approach

Left atrial appendage aneurysm (LAAA) is a rare and underdiagnosed cardiovascular anomaly, with fewer than 200 documented cases in the medical literature. It is often associated with severe complications such as arrhythmias and thromboembolic events. Recent investigations suggest that viral infections, particularly viral myocarditis, might be an underlying cause of LAAA. This association remains underexplored, but it highlights the need for careful clinical investigation when patients present with unexplained arrhythmias following viral infections. We report a 36-year-old woman with a history of asthma, who presented with palpitations and atrial tachyarrhythmia two months post-severe upper respiratory infection. Transthoracic echocardiography revealed a large aneurysmal LAA measuring 5.6 cm x 3.5 cm and a reduced left ventricular ejection fraction of 50%. Cardiac CT confirmed the LAAA with abnormal flow dynamics. The late gadolinium enhancement showed mid-subepicardial hyperenhancement in the posterolateral segments of the left ventricle wall, suggestive of a previous myocarditis The patient underwent a novel minimally invasive endoscopic thoracoscopic resection of the aneurysm, guided by transesophageal echocardiography, without the presence of thrombus. The surgery was performed successfully with the assistance of cardiopulmonary bypass. This case is a first report of potential link between viral myocarditis and LAAA, underscoring the critical role of multimodal imaging in accurate diagnosis and management. The success of minimally invasive surgical resection in restoring cardiac function highlights its effectiveness, offering a promising outlook for patients with LAAA. Clinicians should consider viral infections as potential contributors to LAAA development, advocating for early diagnosis and intervention to enhance clinical outcomes.